platform/gp2x/code940/940.c

   1 // The top-level functions for the ARM940\r
   2 // (c) Copyright 2006-2007, Grazvydas "notaz" Ignotas\r
   3 \r
   4 #include "940shared.h"\r
   5 \r
   6 static _940_data_t *shared_data = (_940_data_t *)   0x00100000;\r
   7 static _940_ctl_t  *shared_ctl  = (_940_ctl_t *)    0x00200000;\r
   8 static unsigned char *mp3_data  = (unsigned char *) 0x00400000;\r
   9 YM2612 *ym2612_940;\r
  10 \r
  11 // from init.s\r
  12 int  wait_get_job(int oldjob);\r
  13 void spend_cycles(int c);\r
  14 void dcache_clean(void);\r
  15 void dcache_clean_flush(void);\r
  16 void drain_wb(void);\r
  17 // this should help to resolve race confition where shared var\r
  18 // is changed by other core just before we update it\r
  19 void set_if_not_changed(int *val, int oldval, int newval);\r
  20 \r
  21 void _memcpy(void *dst, const void *src, int count);\r
  22 \r
  23 //      asm volatile ("mov r0, #0" ::: "r0");\r
  24 //      asm volatile ("mcr p15, 0, r0, c7, c6,  0" ::: "r0"); /* flush dcache */\r
  25 //      asm volatile ("mcr p15, 0, r0, c7, c10, 4" ::: "r0"); /* drain write buffer */\r
  26 \r
  27 \r
  28 static int find_sync_word(unsigned char *buf, int nBytes)\r
  29 {\r
  30         unsigned char *p, *pe;\r
  31 \r
  32         /* find byte-aligned syncword - need 12 (MPEG 1,2) or 11 (MPEG 2.5) matching bits */\r
  33         for (p = buf, pe = buf + nBytes - 4; p < pe; p++)\r
  34         {\r
  35                 int pn;\r
  36                 if (p[0] != 0xff) continue;\r
  37                 pn = p[1];\r
  38                 if ((pn & 0xf8) != 0xf8 || // currently must be MPEG1\r
  39                     (pn & 6) == 0) {       // invalid layer\r
  40                         p++; continue;\r
  41                 }\r
  42                 pn = p[2];\r
  43                 if ((pn & 0xf0) < 0x20 || (pn & 0xf0) == 0xf0 || // bitrates\r
  44                     (pn & 0x0c) != 0) { // not 44kHz\r
  45                         continue;\r
  46                 }\r
  47 \r
  48                 return p - buf;\r
  49         }\r
  50 \r
  51         return -1;\r
  52 }\r
  53 \r
  54 static void mp3_decode(void)\r
  55 {\r
  56         int mp3_offs = shared_ctl->mp3_offs;\r
  57         unsigned char *readPtr = mp3_data + mp3_offs;\r
  58         int bytesLeft = shared_ctl->mp3_len - mp3_offs;\r
  59         int offset; // frame offset from readPtr\r
  60         int retries = 0, err;\r
  61 \r
  62         if (bytesLeft <= 0) return; // EOF, nothing to do\r
  63 \r
  64 retry:\r
  65         offset = find_sync_word(readPtr, bytesLeft);\r
  66         if (offset < 0) {\r
  67                 set_if_not_changed(&shared_ctl->mp3_offs, mp3_offs, shared_ctl->mp3_len);\r
  68                 return; // EOF\r
  69         }\r
  70         readPtr += offset;\r
  71         bytesLeft -= offset;\r
  72 \r
  73         err = MP3Decode(shared_data->mp3dec, &readPtr, &bytesLeft,\r
  74                         shared_data->mp3_buffer[shared_ctl->mp3_buffsel], 0);\r
  75         if (err) {\r
  76                 if (err == ERR_MP3_INDATA_UNDERFLOW) {\r
  77                         set_if_not_changed(&shared_ctl->mp3_offs, mp3_offs, shared_ctl->mp3_len);\r
  78                         return;\r
  79                 } else if (err <= -6 && err >= -12) {\r
  80                         // ERR_MP3_INVALID_FRAMEHEADER, ERR_MP3_INVALID_*\r
  81                         // just try to skip the offending frame..\r
  82                         readPtr++;\r
  83                         bytesLeft--;\r
  84                         if (retries++ < 2) goto retry;\r
  85                 }\r
  86                 shared_ctl->mp3_errors++;\r
  87                 shared_ctl->mp3_lasterr = err;\r
  88         }\r
  89         set_if_not_changed(&shared_ctl->mp3_offs, mp3_offs, readPtr - mp3_data);\r
  90 }\r
  91 \r
  92 static void ym_flush_writes(void)\r
  93 {\r
  94         UINT16 *wbuff;\r
  95         int i;\r
  96 \r
  97         if (shared_ctl->writebuffsel == 1) {\r
  98                 wbuff = shared_ctl->writebuff1;\r
  99         } else {\r
 100                 wbuff = shared_ctl->writebuff0;\r
 101         }\r
 102 \r
 103         /* playback all writes */\r
 104         for (i = 2048; i > 0; i--) {\r
 105                 UINT16 d = *wbuff++;\r
 106                 if (d == 0xffff) break;\r
 107                 if (d == 0xfffe) continue;\r
 108                 YM2612Write_(d >> 8, d);\r
 109         }\r
 110 }\r
 111 \r
 112 static void ym_update(int *ym_buffer)\r
 113 {\r
 114         int i, dw;\r
 115         int two_upds = 0;\r
 116         UINT16 *wbuff;\r
 117 \r
 118         if (shared_ctl->writebuffsel == 1) {\r
 119                 wbuff = shared_ctl->writebuff1;\r
 120         } else {\r
 121                 wbuff = shared_ctl->writebuff0;\r
 122         }\r
 123 \r
 124         /* playback all writes */\r
 125         for (i = 2048/2; i > 0; i--) {\r
 126                 UINT16 d;\r
 127                 dw = *(int *)wbuff;\r
 128                 d = dw;\r
 129                 wbuff++;\r
 130                 if (d == 0xffff) break;\r
 131                 if (d == 0xfffe) { two_upds=1; break; }\r
 132                 YM2612Write_(d >> 8, d);\r
 133                 d = (dw>>16);\r
 134                 wbuff++;\r
 135                 if (d == 0xffff) break;\r
 136                 if (d == 0xfffe) { two_upds=1; break; }\r
 137                 YM2612Write_(d >> 8, d);\r
 138         }\r
 139 \r
 140         if (two_upds)\r
 141         {\r
 142                 int len1 = shared_ctl->length / 2;\r
 143                 shared_ctl->ym_active_chs =\r
 144                         YM2612UpdateOne_(ym_buffer, len1, shared_ctl->stereo, 1);\r
 145 \r
 146                 for (i *= 2; i > 0; i--) {\r
 147                         UINT16 d = *wbuff++;\r
 148                         if (d == 0xffff) break;\r
 149                         YM2612Write_(d >> 8, d);\r
 150                 }\r
 151 \r
 152                 ym_buffer += shared_ctl->stereo ? len1*2 : len1;\r
 153                 len1 = shared_ctl->length - len1;\r
 154 \r
 155                 shared_ctl->ym_active_chs =\r
 156                         YM2612UpdateOne_(ym_buffer, len1, shared_ctl->stereo, 1);\r
 157         } else {\r
 158                 shared_ctl->ym_active_chs =\r
 159                         YM2612UpdateOne_(ym_buffer, shared_ctl->length, shared_ctl->stereo, 1);\r
 160         }\r
 161 }\r
 162 \r
 163 \r
 164 void Main940(void)\r
 165 {\r
 166         int *ym_buffer = shared_data->ym_buffer;\r
 167         int job = 0;\r
 168         ym2612_940 = &shared_data->ym2612;\r
 169 \r
 170 \r
 171         for (;;)\r
 172         {\r
 173                 job = wait_get_job(job);\r
 174 \r
 175                 shared_ctl->lastjob = job;\r
 176 \r
 177                 switch (job)\r
 178                 {\r
 179                         case JOB940_INITALL:\r
 180                                 /* ym2612 */\r
 181                                 shared_ctl->writebuff0[0] = shared_ctl->writebuff1[0] = 0xffff;\r
 182                                 YM2612Init_(shared_ctl->baseclock, shared_ctl->rate);\r
 183                                 /* Helix mp3 decoder */\r
 184                                 shared_data->mp3dec = MP3InitDecoder();\r
 185                                 break;\r
 186 \r
 187                         case JOB940_INVALIDATE_DCACHE:\r
 188                                 drain_wb();\r
 189                                 dcache_clean_flush();\r
 190                                 break;\r
 191 \r
 192                         case JOB940_YM2612RESETCHIP:\r
 193                                 YM2612ResetChip_();\r
 194                                 break;\r
 195 \r
 196                         case JOB940_PICOSTATELOAD:\r
 197                                 YM2612PicoStateLoad_();\r
 198                                 break;\r
 199 \r
 200                         case JOB940_PICOSTATESAVE2:\r
 201                                 YM2612PicoStateSave2(0, 0);\r
 202                                 _memcpy(shared_ctl->writebuff0, ym2612_940->REGS, 0x200);\r
 203                                 break;\r
 204 \r
 205                         case JOB940_PICOSTATELOAD2_PREP:\r
 206                                 ym_flush_writes();\r
 207                                 break;\r
 208 \r
 209                         case JOB940_PICOSTATELOAD2:\r
 210                                 _memcpy(ym2612_940->REGS, shared_ctl->writebuff0, 0x200);\r
 211                                 YM2612PicoStateLoad2(0, 0);\r
 212                                 break;\r
 213 \r
 214                         case JOB940_YM2612UPDATEONE:\r
 215                                 ym_update(ym_buffer);\r
 216                                 break;\r
 217 \r
 218                         case JOB940_MP3DECODE:\r
 219                                 mp3_decode();\r
 220                                 break;\r
 221 \r
 222                         case JOB940_MP3RESET:\r
 223                                 if (shared_data->mp3dec) MP3FreeDecoder(shared_data->mp3dec);\r
 224                                 shared_data->mp3dec = MP3InitDecoder();\r
 225                                 break;\r
 226                 }\r
 227 \r
 228                 shared_ctl->loopc++;\r
 229                 dcache_clean();\r
 230         }\r
 231 }\r
 232 \r